Limit test for iron

This ppt will explains you the limit test for iron , procedure and observation , easy for the students from diploma and bachelor pharmacy course .

1. Limit test for Iron Shikha Agrawal B.Pharm : Naraina Vidyapeeth Group Of Institution

2. PRINCIPLE . The limit test of iron is based on the reaction of iron (ferrous Fe 2+ ) in ammonical solution, in presence of citric acid with Thioglycolic acid gives purple colour . The colour produce by test solution is compared with standard iron solution. The colour develop only in presence of alkali Ammonia to make solution alkaline

3. REACTION PURPLE COLOUR Citric acid Test substance S tandard substance

4. Test substance Standard substance Sample is dissolved in specific amount of water and then volume is made up to 40 ml 2 ml of standard solution of iron diluted with water up to 40ml Add 2 ml of 20 % w/v of citric acid (iron free) Add 2 ml of 20 % w/v of citric acid (iron free) Add 2 drops of thioglycollic acid Add 2 drops of thioglycollic acid Add ammonia to make the solution alkaline and adjust the volume to 50 ml Add ammonia to make the solution alkaline and adjust the volume to 50 ml Keep aside for 5 min Keep aside for 5 min Color developed is viewed vertically and compared with standard solution Color developed is viewed vertically and compared with test solution PROCEDURE

5. OBSERVATION The purple color produce in sample solution should not be greater than standard solution. If purple color produces in sample solution is less than the standard solution, the sample will pass the limit test of iron and vice versa. Means ; the intensity of colour produced by sample is less than that of standard solution colour , it passes the test.

6. THANK YOU